<?php

    namespace lib
    {
        class uuid
        {
            public static function v4()
            {
                return sprintf('%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
                    mt_rand(0, 0xffff), mt_rand(0, 0xffff),
                    mt_rand(0, 0xffff),
                    mt_rand(0, 0x0fff) | 0x4000,
                    mt_rand(0, 0x3fff) | 0x8000,
                    mt_rand(0, 0xffff), mt_rand(0, 0xffff), mt_rand(0, 0xffff)
                );
            }
        }
    }